Clinical Outcomes of Antrectomy for Patients With Multiple Type I Gastric Neuroendocrine Tumors: A Case Series

Objectives Type I gastric neuroendocrine tumors (T1‐GNETs) are frequently associated with autoimmune gastritis and typically present as multiple lesions. The treatment options for T1‐GNETs include endoscopic resection (ER), surgical resection, and pharmaceutical therapies. Antrectomy is reportedly an effective treatment for multiple T1‐GNETs; however, its efficacy and indication remain unclear. In this study, we aimed to assess the efficacy of antrectomy in patients with multiple T1‐GNETs. Methods We retrospectively evaluated the clinical outcomes of eight patients with persistent multiple T1‐GNETs in the gastric remnant following antrectomy from 2005 to 2023. Results All eight patients (median age: 60 years, male‐to‐female ratio 1:3) had body‐dominant atrophic gastritis. Median preoperative serum gastrin levels were 4800 (range, 2400–11,000) pg/mL. Preoperative endoscopy revealed <10 in two, 10–20 in one, and >20 in five patients. Antrectomy was performed as a primary surgery in three patients, as a completion surgery following non‐curative ER in two patients, and a combination therapy with pre‐antrectomy ER in three patients. Median serum gastrin levels decreased to 68 (range, 25–120) pg/mL during the median followup of 56 (range, 14–72 months). Tumor regression was observed in two patients and disappearance in six, with no recurrence or deaths. Conclusion We assessed the residual T1‑GNETs post‐antrectomy and discovered either regression or disappearance in all cases. Normalized serum gastrin levels following antrectomy may have contributed to this outcome. On the basis of our findings, the combination of antrectomy and ER resulted in tumor regression that may represent a potential organ‐preserving approach for patients with multiple T1‐GNETs.